0^6 Journal of Agricultural Research voi. iv. No. 4 



which had made a growth of 8 to 10 inches, showed an occasional leaf 

 spot. The pruned-and-sprayed plot produced an excellent growth, but 

 had some leaf-spot and a few girdled vines. The check showed many 

 dead plants, and none of the living ones were entirely free from disease. 



CONTROL EXPERIMENTS IN 1 9 14 



A writer in Garden (10) states that Bordeaux mixture, when applied 

 to diseased clematis plants, was of no benefit in checking the disease. 

 In 1 91 4, spraying experiments were carried out by the writer on 18 rows 

 (about 300 feet long) of plants of C. jackmanni, half of which were sprayed 

 with Bordeaux mixture (4-4-50 formula) , while the others were left as 

 checks. Four of these, two checks and two sprayed rows, were pruned 

 on June 12 and 25 in such a manner as to remove the dead stubs of the 

 previous year. Plants from which all of the discolored tissue could not 

 be removed without injury to the entire vine were marked with tags. 

 The rows receiving Bordeaux mixture were sprayed every two weeks. 

 The final examination was made on October 19. No difference could be 

 seen between the sprayed and the check rows either in the amount of 

 leaf spot or the number of dead plants. The same held true for the 

 pruned and unpruned rows. However, there was but little leaf-spot, 

 and it was observed that the dead plants in the pruned rows were inva- 

 riably plants that had been tagged. No doubt the pruning was done too 

 late in the season to be of any benefit. Sulphur dusted on cuttings in the 

 forcing frames did not check the disease. Plants in the greenhouse 

 sprayed with soap-and-sulphur mixture so as to cover the leaves with a 

 thin film were healthier than the unsprayed plants. These, however, 

 were not carried through the second season, and hence the ultimate 

 results are imknown. 



Two long, narrow beds of C. paniculata were utilized for spraying and 

 dusting experiments in 1914. Bed i consisted of yearling plants 

 untreated in 191 3. Bed 2 contained 2 -year-old plants pruned and 

 sprayed with Bordeaux mixture in 191 3. Both beds were divided into 

 plots 6 by 25 feet in size. 



Two plots in each bed were sprayed with Bordeaux mixture six times 

 at intervals of two weeks from May 15 to August 8. On the same dates 

 one plot in each bed was sprayed with a soap-and-sulphur mixture com- 

 posed of I pound of soap, 6 pounds of sulphur, and 15 gallons of water. 

 Two and one-half gallons of the mixture, containing i pound of sulphur, 

 were used on each plot at each application. On two plots in bed i and 

 one plot in bed 2 the plants were dusted six times with sulphur, using i 

 pound to the plot at each application. The remaining eight plots (three 

 in bed i and five in bed 2) were left untreated for checks. 



As the season advanced, the virulence of the disease increased, becom- 

 ing quite severe on all three check plots in bed i and one check plot in bed 



